Thomasburg is a small hamlet in the Municipality of Tweed in eastern Ontario. Behind my home here is a fallow field, swamp, cedar bush, old apple orchard and woods. Almost every day I take the same walk through this territory to see who's been by, and try to figure out what they've been up to.

Tuesday, July 12, 2005

Where the snakes are.....

Some years are snake years--some years are not. This summer has all the makings of a snake year, hot, still, hazy (we're back in the smog again), but I haven't seen many snakes. The season started with great promise. On May 28 I was sitting on the front porch, glanced across the street and saw a suspicious long thin object sprawled out on the road. I quickly ducked in the house for my shoes, and when I stepped out again I could see that the object had moved--my first instinct had been right, a snake and alive. I started walking over, hoping I would get to it before a car came by.

It was a milk snake, Lampropeltis triangulum, about a metre long but very slim. As I approached it reared up, coiled back and started to vibrate its tail. I managed to chase it off the road in spite of its recurrently diplayed willingness to stand and fight.

In the literature milk snakes are sometimes described as docile, sometimes as feisty, and I have seen both. A couple of years ago I saw my neighbour across the street chasing something on her stoup with a hoe. After a moment or two I realized to my horror that she was chasing a snake. Calling out that I would help I rushed over. That too was a milk snake, but very calm, especially considering the circumstances. It was uninjured (my neighbour told me that she didn't want to hurt the snake, but she couldn't bear for it to be so close to the house), and allowed me to pick it up with no difficulty at all. I carried it back across the street and let it loose in the tall grass at the edge of the yard.

Milk snakes are a species of concern. It is not thought that they are endangered, but because of the habits described above there is believed to be a lot of pressure on their population. The habit of coiling back as if to strike and vibrating the tail puts people in mind of the rattlesnake, as it is intended to do, of course. But people react to the thought of a rattlesnake by killing. The habit of lying on the road leads to death by automobile. So, like so many other species, the primary threat to the milk snake is us.

Because of its status as a species of concern, the Natural Heritage Information Centre (Ontario) collects reports of sightings of this species at their Web site.

Identifying a milk snake is not as easy as I once thought. We see them here every year, some years more than others, and for a while I was convinced that some of the snakes I saw were the much rarer fox snake. The fox snake is provincially rare, and non-existent in eastern Ontario, yet I was not the only one to believe that we had them here in Thomasburg.

The fox snake also vibrates its tail when threatened (and is found in an area where there actually are some rattlesnakes, southwestern Ontario), and is to my eyes quite similar in its markings to the milk snake. Here's a link to a site that has images and descriptions of all the lizards and snakes in Ontario. If you look at the images on the site given you'll see two snakes that look quite different. The milk snake there has much greater contrast between the marks and background on its back, and looks more red than beige. I've seen snakes around here that look like that one, and more, that are very red, with very sharp contrast, and a very clear black-and-white checkered pattern on their bellies (fox snakes also have this belly feature, but with a yellow rather than white background to the markings). These snakes also tend to be very small. It turns out though that as they grow milk snakes tend to become much more brown or beige, and lose that sharp contrast between foreground and background markings. Older milk snakes also tend to be quite large and heavy, generally much heavier than the snake I chased off the road this spring.

So, two years ago I spent some months and many e-mails to various experts trying to establish that there were fox snakes here--sure that the big heavy beige and brown snakes I'd seen had to be these. Finally I found another way to distinguish the species. The fox snake has a divided anal plate, the milk snake does not (there are other species with divided anal plates that might have been part of this story, but as it turned out they were moot). The anal plate is just what is sounds like, a plate on the underside of the snake at the anus.

The controversy ended with the death by car of a snake here in the hamlet. It was one of the mystery snakes, and the accident left the anal plate intact. If you get a good look at the underside of a snake this is a very easy field mark to recognize. The snake had a single anal plate, hence milk snake.

But now there's the black rat snake--a new controversy in the making. The black rat snake is found in eastern Ontario, but only in a few places, primarily Frontenac Provincial Park (east of Thomasburg, due north of Kingston). It is a big snake, and, of course, black. Neighbours in the hamlet report that they have seen this snake, and this year I almost believe (ever hopeful of a sighting of the rare) that I almost saw one a few weks ago. Standing in the driveway, saying goodbye to guests, my arms full of a tomato plant I was carrying down to the car for them I saw just a bit of a very large, very dark snake in the grass. It slithered away before I could get organized to go over for a better look. I've been keeping my eyes peeled ever since.....